Optoelectronic Semiconductor Component

ABSTRACT

An optoelectronic semiconductor component comprising a connection carrier with a mounting face and an electrically insulating base member. An optoelectronic semiconductor chip is arranged on the mounting face of the connection carrier. A radiation-transmissive body having four side faces is provided. The radiation-transmissive body surrounds the semiconductor chip in such a way that the radiation-transmissive body envelops outer faces of the optoelectronic semiconductor chip not facing the connection carrier in form-fitting manner. The radiation-transmissive body comprises at least one side face which extends at least in places at an angle of between 60° and 70° to the mounting face. The base member has a thickness which amounts to at most 250 μm.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. Ser. No. 14/793,096 filed Jul.7, 2015 which is a divisional of U.S. patent application Ser. No.13/056,811 filed Apr. 22, 2011 (now U.S. Pat. No. 9,099,622) which is aU.S. national stage of application No. PCT/DE2009/000988 filed Jul. 15,2009 which claims priority of German patent application no. 10 2008 035255.1, filed Jul. 29, 2008, the disclosure contents of all of which arehereby incorporated by reference.

FIELD OF THE INVENTION

An optoelectronic semiconductor component is provided.

SUMMARY OF THE INVENTION

According to at least one embodiment of the optoelectronic semiconductorcomponent, the optoelectronic semiconductor component comprises aconnection carrier. The connection carrier comprises for example acircuit board, which comprises a base member consisting of anelectrically insulating material. Electrical connection tracks andconductive tracks may be structured on and/or in the base member.

According to at least one embodiment of the optoelectronic semiconductorcomponent, the optoelectronic semiconductor component comprises anoptoelectronic semiconductor chip. The optoelectronic semiconductor chipcomprises a radiation-emitting or radiation-receiving semiconductorchip. For example, the optoelectronic semiconductor chip is aluminescent diode chip, that is to say that the optoelectronicsemiconductor chip takes the form of a light-emitting diode chip or alaser diode chip. The optoelectronic semiconductor chip is arranged on amounting face of the contact carrier, to which the optoelectronicsemiconductor chip may be attached mechanically and electricallycontacted.

According to at least one embodiment of the optoelectronic semiconductorcomponent, the optoelectronic semiconductor component comprises aradiation-transmissive body, surrounding the semiconductor chip. Theradiation-transmission body comprises for example an encapsulating bodyof an encapsulating material, with which the semiconductor chip isencapsulated. The radiation-transmissive body preferably envelops thesemiconductor chip in a form-fitting manner, that is to say thesemiconductor chip is embedded in the material of theradiation-transmissive body and its faces which do not face theconnection carrier are surrounded in form-fitting manner by the materialof the radiation-transmissive body. At said faces theradiation-transmissive body is for example in direct contact with thesemiconductor chip. The radiation-transmissive body is in this casetransmissive at least for some of the electromagnetic radiationgenerated by the semiconductor chip when in operation.

According to at least one embodiment of the optoelectronic semiconductorcomponent, the radiation-transmissive body contains a silicone. Theradiation-transmissive body may here consist of silicone. It isadditionally possible for particles of other materials such as forexample diffuser particles, radiation-absorbing particles or particlesof a luminescence conversion material to be introduced into theradiation-transmissive body. It is furthermore possible for theradiation-transmissive body to be made of a silicone-epoxy hybridmaterial. The radiation-transmissive body then comprises for example 50%epoxy material and 50% silicone.

According to at least one embodiment of the optoelectronic semiconductorcomponent, the radiation-transmissive body comprises at least one sideface, which extends at least in places at an angle of <90° to themounting face, that is to say the side face does not extendperpendicularly to the connection carrier. The side face is thus notperpendicular to the mounting face of the connection carrier. Instead,at least part of the side face forms an angle of <90° with the mountingface. The fact that the side face forms an angle of <90° with themounting face of the connection carrier also means that the side facehas a slope angle of >0°. The slope angle is the angle which the sideface forms with a surface normal to the mounting face of the connectioncarrier.

The side face is in this case preferably substantially planar and theentire side face forms an angle of <90° with the mounting face of theconnection carrier. “Substantially planar” means that the side face mayexhibit roughness, but that the macroscopic profile of the side face ishowever planar or smooth.

All in all, according to at least one embodiment the optoelectronicsemiconductor component thus comprises a radiation-transmissive bodywhich comprises at least one bevelled or sloping side face. Theradiation-transmissive body is thus not cuboidal in configuration, butrather has at least one bevelled side face.

According to at least one embodiment of the optoelectronic semiconductorcomponent, the side face is produced by a singulation process, that isto say the side face is not produced by an encapsulating method using amould but rather the bevelled or sloping side face is produced by asingulation process. This further means that the side face exhibitstraces of a singulation process. For example, the side face bears tracesof material abrasion. The feature that the side face “is produced by asingulation process” is thus a product-related feature, which isdetectable on the finished optoelectronic semiconductor component as aresult of the singulation traces. The roughness of the side faceproduced by the singulation process here depends on the material of theradiation-transmissive body and on the singulation means used, forexample on the saw blade used.

According to at least one embodiment of the optoelectronic semiconductorcomponent, the optoelectronic semiconductor component comprises aconnection carrier, an optoelectronic semiconductor chip, which isarranged on a mounting face of the connection carrier, and aradiation-transmissive body, which surrounds the semiconductor chip, theradiation-transmissive body containing a silicone and theradiation-transmissive body comprising at least one side face whichextends at least in places at an angle of <90° to the mounting face, theside face being produced by a singulation process.

The optoelectronic semiconductor component is based inter alia on thefollowing recognition: conventionally, a radiation-transmissiveencapsulating body is given the desired shape by an encapsulatingprocess. The encapsulating body has to be adjusted to the optoelectronicsemiconductor chip. This adjustment of encapsulating body tooptoelectronic semiconductor chip is complicated. In addition, it iscomplicated to produce connection carriers with the necessary smalltolerances. If side faces of the radiation-transmissive body areproduced by a singulation process after encapsulation, and the opticalshape of the radiation-transmissive encapsulating body is thus notdefined until after encapsulation, it is particularly simple to changethe shape of the radiation-transmissive body and adjust the actualposition of the optoelectronic semiconductor chip on the mounting faceof the connection carrier. For example, adjustment marks may be presenton the mounting face of the connection carrier, with the assistance ofwhich the sloping side faces of the radiation-transmission body may beparticularly precisely produced. It has, moreover, been found thatbevelled or sloping side faces of the radiation-transmissive body helpto increase the efficiency with which electromagnetic radiationgenerated in the semiconductor chip is outcoupled by theradiation-transmissive body out of the optoelectronic semiconductorcomponent.

According to at least one embodiment of the optoelectronic semiconductorchip, the at least one side face, which extends at least in places at anangle of <90° to the mounting face, is produced by a sawing process,that is to say the side face then exhibits traces of a sawing process.The side face may for example comprise grooves, which were produced bythe saw blades with which the side face was produced.

According to at least one embodiment of the optoelectronic semiconductorcomponent, the radiation-transmissive body comprises at least one sideface, which extends at least in places at an angle of between 60° and70° to the mounting face and is produced by a singulation process. Ithas been found that the angular range of between 60° and 70° betweensloping side face and mounting face may be ideal in terms of theoutcoupling of electromagnetic radiation out of theradiation-transmissive body. Outcoupling efficiency may be increased byup to 13% relative to side faces which extend at a 90° angle to themounting face of the connection carrier.

According to at least one embodiment of the optoelectronic semiconductorcomponent, the radiation-transmissive body comprises at least two sidefaces, which extend at least in places at an angle of <90° to themounting face and are in each case produced by a singulation process.Preferably, the at least two side faces extend in an angular range ofbetween 60° and 70° to the mounting face.

Particularly preferably, four side faces of the radiation-transmissivebody extend at an angle of between 60° and 70° to the mounting face andare produced by a singulation process. The four side faces are here ofsubstantially planar configuration, that is to say apart fromsingulation traces on the side faces said side faces extend in planarmanner.

This means that the radiation-transmissive body takes the form of atruncated pyramid. The side faces of the truncated pyramid are hereproduced by a singulation process, in particular by a sawing process.The side faces preferably form an angle of <90°, particularly preferablyan angle of between 60° and 70°, with the mounting face of theconnection carrier. The truncated pyramid comprises a rectangular, forexample a square base area, for example.

According to at least one embodiment of the optoelectronic semiconductorcomponent, the radiation-transmissive body directly adjoins the mountingface of the connection carrier, that is to say theradiation-transmissive body is in direct contact with the mounting faceof the connection carrier. It is additionally possible for at least onelayer, for example a foil, to be arranged between radiation-transmissivebody and connection carrier, which layer increases adhesion between theradiation-transmissive body and the connection carrier. The layer may,for example, comprise a silicone foil.

According to at least one embodiment of the optoelectronic semiconductorcomponent, the connection carrier is made of a ceramic material. Theconnection carrier may for example comprise a base member which consistsof a ceramic material such as aluminium nitride or aluminium oxide.Electrical connection tracks and/or conductive tracks may be structuredon the base member at the connection carrier mounting face. These mayfor example take the form of metal coatings, which are vapour-depositedonto the base member or applied in some other way.

It is furthermore possible for the connection carrier to comprise atleast two electrical connection points on its base member, on the sideremote from the mounting face, by means of which connection points thesemiconductor chip of the optoelectronic semiconductor component may beelectrically contacted. In this case the optoelectronic semiconductorcomponent is of surface-mountable configuration. The connection pointsmay in this case be connected with connection points and conductivetracks on the mounting face of the connection carrier by means ofopenings in the base member of the connection carrier or via metalcoatings, which extend along side faces of the connection carrier.

According to at least one embodiment of the optoelectronic semiconductorcomponent, a planarisation layer is applied to at least one side face ofthe radiation-transmissive body, which side face is produced by asingulation process. As a result of producing the side face by asingulation process, the side face comprises singulation traces. Thesesingulation traces may lead to optical disturbance of the exiting light.For example, the light passing through the side face may be undesirablyrefracted or scattered at these singulation traces. To prevent suchrefraction or scattering, a planarisation layer may be applied to theside face, which layer evens out the unevennesses caused by thesingulation traces. A layer of silicone is sprayed onto the side face,for example.

A method of producing an optoelectronic semiconductor component isadditionally provided. The method preferably allows production of anoptoelectronic semiconductor component as described in relation to atleast one of the preceding embodiments, that is to say all the featuresdisclosed in relation to the optoelectronic semiconductor component arealso disclosed in relation to the method.

The method preferably comprises the following steps:

providing a connection carrier,

attaching and electrically contacting an optoelectronic semiconductorchip to a mounting face of the connection carrier,

moulding a radiation-transmissive body around the optoelectronicsemiconductor chip and

sawing the radiation-transmissive body at an angle of <90° to themounting face of the connection carrier in order at least in places toproduce a side face of the radiation-transmissive body.

The optical shape of the radiation-transmissive body is defined by asingulation process, for example a sawing process. The shape of theradiation-transmissive body may be readily modified by different shapedsaw blades, which are quick and easy to change. When conventionalencapsulating methods are used, this is associated with considerablecosts for modifying or producing the mould. Moreover, in conventionalencapsulating methods, connection carrier production tolerances have tobe kept very small or additional complex process steps such as anadjusting step have to be carried out, in order to keep the relativeposition of the optical system, i.e. of radiation-transmissive body andchip, within acceptable limits. Connection carriers with smalltolerances are significantly more expensive. In the method describedherein, saw markings on the connection carrier, for example, which inconventional methods merely assist in the sawing process for singulatingthe components, simultaneously define the position of the optical systemrelative to the semiconductor chip.

According to at least one embodiment of the method, theradiation-transmissive body is produced by means of compressionmoulding, liquid transfer moulding, liquid injection moulding orcasting, wherein the connection carrier may form part of the mould.Compression moulding is an effective method of producing encapsulatingbodies for semiconductor chips. In this process, the material for theencapsulating body is introduced into the mould and the connectioncarrier is pressed into the material located in the mould.

In a modification of compression moulding, solid, granular material mayalso be used, for example silicone-epoxy hybrid material. In this case,the material may also be applied to the connection carrier and thesemiconductor chip before the mould is closed. The seal betweenconnection carrier and mould may be brought about for example by way ofa sealing foil, which is removed after the compression moulding process.

If solid materials, for instance hybrid materials, pressed into tabletshape for example, are used, the encapsulating body may also be producedby means of transfer moulding.

Document WO 2005/017995 A1 describes liquid injection moulding ofsemiconductor components, for example. Casting of semiconductorcomponents is described in document EP 1 589 569 A2 and liquid transfermoulding of integrated semiconductor circuits is described in documentUS 2002/0153637 A1. These documents are hereby expressly included byreference with regard to the methods described therein.

According to at least one embodiment of the method, a planarisationlayer is sprayed onto the sawn side faces of the radiation-transmissivebody once the sawn side face has been produced. The planarisation layerplanarises singulation traces in the radiation-transmissive body.

Other objects and features of the present invention will become apparentfrom the following detailed description considered in conjunction withthe accompanying drawings. It is to be understood, however, that thedrawings are designed solely for purposes of illustration and not as adefinition of the limits of the invention, for which reference should bemade to the appended claims. It should be further understood that thedrawings are not necessarily drawn to scale and that, unless otherwiseindicated, they are merely intended to conceptually illustrate thestructures and procedures described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

The optoelectronic semiconductor component described herein is explainedin greater detail below with reference to exemplary embodiments and theassociated figures:

FIG. 1A is a schematic sectional representation of an optoelectronicsemiconductor component described herein according to a first exemplaryembodiment.

FIG. 1B shows an enlarged portion of an optoelectronic semiconductorcomponent described herein in a second exemplary embodiment.

FIG. 1C schematically plots outcoupling efficiency as a function ofsurface scattering for one exemplary embodiment of an optoelectronicsemiconductor component described herein.

FIG. 2 is a schematic perspective representation of an optoelectronicsemiconductor component described herein according to a furtherexemplary embodiment.

FIG. 3 shows simulations of outcoupling efficiency as a function ofslope angle for one exemplary embodiment of an optoelectronicsemiconductor component described herein.

FIG. 4 shows simulations of outcoupling efficiency as a function of thethickness of the base member of the connection carrier for one exemplaryembodiment of an optoelectronic semiconductor component describedherein.

DETAILED DESCRIPTION OF THE DRAWINGS

Identical, similar or identically acting elements are provided with thesame reference numerals in the Figures. The Figures and the size ratiosof the elements illustrated in the Figures relative to one another arenot to be regarded as being to scale. Rather, individual elements may beillustrated on an exaggeratedly large scale for greater ease ofdepiction and/or better comprehension.

FIG. 1A is a schematic sectional representation of an optoelectronicsemiconductor component described herein according to a first exemplaryembodiment. The semiconductor component comprises an optoelectronicsemiconductor chip 1. In this case, the optoelectronic semiconductorchip 1 is a light-emitting diode chip, of thin-film construction.Light-emitting diode chips of thin-film construction are described forexample in documents WO 02/13281 A1 and EP 0 905 797 A2, the disclosurecontent of which is hereby expressly included by reference with regardto the thin-film construction of light-emitting diode chips.

The optoelectronic semiconductor chip 1 is applied to the mounting face22 of a connection carrier 2. The connection carrier 2 further comprisesa base member 20, which is here made of a ceramic material. Electricalconnection points 21 are applied to the bottom, opposite the mountingface 22, of the base member 20 of the connection carrier 2, by way ofwhich connection points 22 the optoelectronic semiconductor component issurface-mountable. The optoelectronic semiconductor chip 1 isencapsulated in a radiation-transmissive body 3.

The radiation-transmissive body 3 envelops the optoelectronicsemiconductor chip 1 in form-fitting manner. The radiation-transmissivebody 3 here consists of a silicone. The radiation-transmissive body 3directly adjoins the mounting face 22 of the connection carrier 2. Theradiation-transmissive body 3 comprises side faces 30. The side faces 30extend in planar manner, apart from singulation traces 31, which areshown exaggeratedly large in FIG. 1A to make them more visible. The sidefaces 30 form an angle β of <90° with the mounting face 22 of theconnection carrier 2, that is to say the slope angle α, which isobtained from the angle of the side face 30 with the surface normal 23to the mounting face 22, is >0°.

The side faces 30 are produced by a sawing process. The singulationtraces 31 comprise saw grooves or other defects such as for exampleindentations, which arise when material is “torn out” of theradiation-transmissive body 3 during sawing.

The optoelectronic semiconductor chip 1 may be arranged centred relativeto the radiation-transmissive body 3 and to the connection carrier 2,that is to say the optical axis 4 through the centre of the radiationexit face 10 of the optoelectronic semiconductor chip 1 then constitutesan axis of symmetry of the optoelectronic semiconductor component. Theabove-described centring is desirable above all with regard toparticularly symmetrical emission. However, non-centred configurationsare also possible.

The optoelectronic semiconductor chip 1 is adjusted relative to theradiation-transmissive body 3 during the singulation process for exampleby means of adjustment marks, not shown, on the mounting surface 22 ofthe connection carrier 2.

FIG. 1B shows an enlarged portion of an optoelectronic semiconductorcomponent described herein according to a second exemplary embodiment.Unlike the exemplary embodiment described in conjunction with FIG. 1A,in this exemplary embodiment a planarisation layer 5 has been arrangedon the side face 30 produced by a singulation process. The planarisationlayer 5 has in this case been sprayed onto the side face 30. Theplanarisation layer 5 here consists of silicone. The planarisation layer5 evens out the unevennesses of the side face 30 produced by thesingulation traces 31.

To this end, FIG. 1C shows a schematic plot of outcoupling efficiency inthe case of a slope angle α of 25° as a function of surface scatteringat the radiation-transmissive body 3. It is assumed that theradiation-transmissive body consists of silicone and has a height H of400 μm. The base member 20 of the connection carrier 2 consists of aceramic material and has a thickness D of 200 μm. It is apparent fromFIG. 1C that outcoupling efficiency falls with increasing surfacescattering at side faces 30 of the radiation-transmissive body 3.Unevennesses on the side faces 30 of the radiation-transmissive bodyincrease surface scattering. The planarisation layer 5 therefore provesparticularly advantageous with regard to outcoupling efficiency.

A further exemplary embodiment of an optoelectronic semiconductorcomponent described herein is explained in greater detail in conjunctionwith the schematic perspective representation of FIG. 2.

As is clear from FIG. 2, the radiation-transmissive body 3 takes theform of a truncated pyramid, which comprises four sloping side faces 30,which are produced by means of a singulation process, in the presentcase sawing.

The connection carrier 2 comprises a base member 20 of a ceramicmaterial, which has a thickness D of preferably at least 0.2 mm and atmost 0.5 mm, for example 0.4 mm. The radiation-transmissive body 3 has aheight H preferably of between 0.55 mm and 0.25 mm, for example of 0.35mm. The sum of the thickness of the main body 20 and height H of theradiation-transmissive body 3 preferably amounts to between 0.7 mm and0.8 mm, for example 0.75 mm.

The slope angle α amounts for example to 25°. The area of the top face32 of the radiation-transmissive body preferably amounts to between 2.0and 2.5 mm², for example 2.3 mm².

The connection carrier 2 has a base area, for example, of 2.04 mm×1.64mm.

The optoelectronic semiconductor chip 1 comprises a radiation exit face10, which may have an area of 500 μm² to 1.5 mm², for example 1.0 mm².The radiation exit face 10 may be square.

FIG. 3 shows simulation results for the outcoupling efficiency of anoptoelectronic semiconductor component, as shown in conjunction withFIG. 2.

As may be inferred from FIG. 3, outcoupling efficiency reaches itsmaximum for a slope angle α=25°. Outcoupling efficiency is increased byaround 13% over a structure with a slope angle=0°. The maximum aroundthe slope angle of 25° is relatively flat, resulting in a wide angulartolerance range of +/−5° for optimum outcoupling, so providing a wideprocess window for mass production of the optoelectronic semiconductorcomponent. The preferred angular range for the slope angle is thereforebetween 20° and 30°, preferably 25°. This ideal angle is however alsodependent on the size of the base area of the connection carrier 2 andmay therefore differ for larger structures. It is important for theradiation-transmissive body to comprise at least one side face 30 whichextends at least in places at an angle β of <90° to the mounting face22.

FIG. 4 shows simulation results for the outcoupling efficiency of anoptoelectronic semiconductor component, as shown in conjunction withFIG. 2. Outcoupling efficiency is here plotted against the thickness Dof the main body 20 of the connection carrier 2. The height H of theradiation-transmissive body 3 is selected in each case such that the sumof thickness D and height H is 750 μm. As may be inferred from thefigure, the outcoupling efficiency is greater, the thinner is theconnection carrier. A thickness of the main body D of at most 250 μm istherefore preferred.

The description made with reference to exemplary embodiments does notrestrict the invention to these embodiments. Rather, the inventionencompasses any novel feature and any combination of features, includingin particular any combination of features in the claims, even if thisfeature or this combination is not itself explicitly indicated in theclaims or exemplary embodiments.

Thus, while there have shown and described and pointed out fundamentalnovel features of the invention as applied to a preferred embodimentthereof, it will be understood that various omissions and substitutionsand changes in the form and details of the devices illustrated, and intheir operation, may be made by those skilled in the art withoutdeparting from the spirit of the invention. For example, it is expresslyintended that all combinations of those elements and/or method stepswhich perform substantially the same function in substantially the sameway to achieve the same results are within the scope of the invention.Moreover, it should be recognized that structures and/or elements and/ormethod steps shown and/or described in connection with any disclosedform or embodiment of the invention may be incorporated in any otherdisclosed or described or suggested form or embodiment as a generalmatter of design choice. It is the intention, therefore, to be limitedonly as indicated by the scope of the claims appended hereto.

What is claimed is:
 1. An optoelectronic semiconductor componentcomprising: a connection carrier with a mounting face and anelectrically insulating base member; an optoelectronic semiconductorchip, which is arranged on the mounting face of the connection carrier;and a radiation-transmissive body having four side faces, wherein theradiation-transmissive body surrounds the semiconductor chip in such away that the radiation-transmissive body envelops outer faces of theoptoelectronic semiconductor chip not facing the connection carrier inform-fitting manner, wherein the radiation-transmissive body comprisesat least one side face which extends at least in places at an angle ofbetween 60° and 70° to the mounting face, and wherein the base memberhas a thickness which amounts to at most 250 μm.
 2. The optoelectronicsemiconductor component according to claim 1, wherein the base member ismade of a ceramic material.
 3. The optoelectronic semiconductorcomponent according to claim 1, wherein the radiation-transmissive bodyhas a height and wherein the sum of the thickness of the base member ofthe connection carrier and the height of the radiation-transmissive bodyamounts to at least 700 μm and at most 800 μm.
 4. The optoelectronicsemiconductor component according to claim 1, wherein the thickness ofthe base member is at least 100 μm.
 5. The optoelectronic semiconductorcomponent according to claim 1, wherein the at least one side face,which extends at least in places at an angle of between 60° and 70° tothe mounting face, is produced by a singulation process.
 6. Theoptoelectronic semiconductor component according to claim 1, wherein theradiation-transmissive body directly adjoins the mounting face of theconnection carrier.
 7. The optoelectronic semiconductor componentaccording to claim 1, wherein a planarisation layer is applied to the atleast one side face of the radiation-transmissive body, which side faceis produced by a singulation process.
 8. An optoelectronic semiconductorcomponent comprising: a connection carrier with a mounting face; anoptoelectronic semiconductor chip, which is arranged on the mountingface of the connection carrier; and a radiation-transmissive body havingfour side faces, wherein the radiation-transmissive body surrounds thesemiconductor chip in such a way that the radiation-transmissive bodyenvelops outer faces of the optoelectronic semiconductor chip not facingthe connection carrier in form-fitting manner, wherein theradiation-transmissive body comprises at least one side face whichextends at least in places at an angle of less than 90° to the mountingface, and wherein the optoelectronic semiconductor chip is arrangednon-centered relative to the radiation-transmissive body.